Ive only started on drawing out the protection board circuit,
Not really decided on what it will do, just been thinking of what I would like it to do,
Originally I liked the idea of pulling power from the amp supply, but thats undecided at the moment, might use a secondary transformer, and features would be taken into consideration.

Thanks for the link OnAudio, but each amp has its own Filtering,
thats what confuses me.

Or should the idea of each module having its own capacitor filtering be changed to
-local decoupling, with modules fed from singular big capacitor bank.

None of the boards to be used in final project have been etched yet, just some prototypes,
If I need to make changes and re-etch boards that ok,
using this as a hoby and learning experience,
so taking it slowly and redoing things untill Im happy with the result

ummm, if Naim, big fat capacitor local to the transformer / rectifier then feeding power to boards with smaller local decoupling. Think of the big fat cap as a (+) and (-) star point if taking this approach.

But for me I like the idea of big local decoupling fed from stars at the rectifier, (+) rectified feed possibly via a small valued power resistor (or choke) to somewhat separate the PSUs of each channel.

You seem to be connecting dirty grounds (e.g. transformer secondary CT) to clean grounds (e.g. star point). Everyone does this, but I don't know why because it guarantees buzz.

First make sure you amp PCBs have a dirty ground connection for the smoothing caps and a clean ground connection for signals. These two grounds can be/must be connected on the PCB. Each dirty ground should go to the CT. The existing thick lead from CT to star ground must be removed. The clean grounds from the amp PCBs should go to star ground.

Doing this will keep charging pulses away from the star ground but you will have ground loops. Unavoidable if you have one secondary/bridge feeding two separate cap banks and amps on two separate PCBs. The whole amp architecture, including PCB design, must take account of grounding.